Door lock

ABSTRACT

A door lock is provided which is capable of use as a night latch. It includes a pin tumbler cylinder lock so that the key can only be removed when the lock is in a locked position, a pinion engaging with a rack on a bolt adapted to be retained in a recess in the jamb of the door frame, when the door is closed, by a latching mechanism, lying perpendicular to the bolt. The latching mechanism is provided with a release mechanism whereby the door lock can be easily opened in an emergency by, for example, a child whereby the door can be quickly opened and the child escape through the door opening.

United States Patent Watson 1 Feb.1,1972

[54] DOOR LOCK 211 Appl. No.: 36,006

[30] Foreign Application Priority Data May 14, 1969 Canada ..051538 [52] U.S. Cl ..70/92, 70/134, 292/142, 292/341.15

[51 Int. Cl ..E05c 15/02, E05b 15/02 [58] Field 01 Search ..70/l34, 129, 92; 292/142, 175, 292/34l.15, 171

[56] References Cited UNITED STATES PATENTS 305,294 9/ 1 884 Corn ..292/ 175 1,707,694 4/1929 Torrence ..70/ 129 313,464 3/1885 Worley ....292/341.15 1,304,334 5/1919 Long... ..292/l75 1,720,590 7/ 1929 Evans ..70/129 2,609,222 9/ 1952 Severson .z ..292/175 Primary Examiner-Albert G. Craig, .lr. Attorney-B. P. Fishbume, Jr.

[57] ABSTRACT A door lock is provided which is capable of use as a night latch. It includes a pin tumbler cylinder lock so that the key can only be removed when the lock is in a locked position, a pinion engaging with a rack on a bolt adapted to be retained in a recess in the jamb of the door frame, when the door is closed, by a latching mechanism, lying perpendicular to the bolt. The latching mechanism is provided with a release mechanism whereby the door lock can be easily opened in an emergency by, for example, a child whereby the door can be quickly opened and the child escape through the door openmg.

4 Claims, 4 Drawing Figures noon LOCK BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improved door lock, and is particularly applicable to the night latch type of door lock where a key must be used to unlock and lock the door from the outside.

2. Description of the Prior Art There are many situations, for example, fire, accident, etc., where an inhabitant of a building requires to escape therefrom as quickly as possible when an emergency occurs. This can be difficult with a normal door lock when the inhabitant is elderly, injured, or is a child of not too great a height.

SUMMARY OF THE INVENTION It is an object of the invention to provide a door lock, capable of use as a night latch, which can only be opened with a key from accordingly by a broad aspect of this invention a combined door lock and night latch is provided comprising the following three integers namely: (i), a door lock comprising (a) a plate adapted to be mounted on the inside face of a door; (b) a pin tumbler cylinder lock extending through said plate and operated by a key which is insertable and removable therefrom only when the cylinder is at one designated position; (c) a shaft member extending from said pin tumbler cylinder lock to project beyond the inside face of the door; (d) a pinion fixed to the shaft member; (e) a bolt provided with a rack adapted to engage the pinion for operation of the bolt and (f) guides to retain the bolt in a substantially horizontally slidably movable position. (ii), a recess adapted to be provided in the jamb of a doorframe and into which the bolt is adapted to slide. (iii), latch means mounted on the doorjamb to retain the bolt in the recess therein when the door is closed, the latch means comprising (g) a retractable latch member, movable perpendicularly to said bolt between a first protruding position in which the bolt is positively retained in the recess, and a second retracted position in which the bolt is no longer positively retained in the recess and permitting opening of the door; (h) a rodlike member connected to the latch member and extending away from the recess; and (i) a chainlike member connected to the rodlike member handing down therefrom, whereby on pulling of the chainlike member, the latch member is moved to its second, retracted position to enable emergency opening of the door.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. I, is a side elevational view of a lock according to the invention illustrating the plate, lock bar or bolt, tumbler and bolt holders;

FIG. 2, is a rear elevational view of a door lock constructed in accordance with the present invention;

FIG. 3, is a side view of the spring-loaded strike bar and operating handle of the door lock; and

FIG. 4, is an assembled view of the door lock mounted for operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in which similar reference numerals designate corresponding parts throughout the different figures, it will be seen that the door lock comprises a metal plate 5 provided with a pin tumbler cylinder lock 6.

As is common with this type of lock, the tumbler lock 6 is provided with a shaft member 7 on which is mounted a pinion 8. A bolt 9 formed with a rack 10 engages said pinion 8 and is activated thereby when a key is inserted in the cylinder. The bolt 9 is retained in position by a pair of guides 11, one at each end thereof within which said bolt slides horizontally between its locking and unlocking positions.

As illustrated in FIG. 4 of the accompanying drawings, the plate 5 is mounted on the inner face of a door, by way of apertures provided therein, whilst the cylinder lock 6 extends through the plate and is mounted through the door and a flange 22 (FIG. 1) retains it in position. The plate is positioned at the edge of the door to permit the bolt 9 to register within a recess 12 which is formed in the jamb of the doorframe in direct alignment with said bolt.

Latch means is mounted on the frame of the door to retain the bolt 9 in the recess 12 when the door is closed. The latch means comprises a retractable latch member 13 movable at the right angle to the bolt 9 between a first protruding position in which the entrance to the recess 12 is blocked and so the bolt 9 is positively retained in the recess 12 and a second retraced position in which the entrance to the recess 12 is unhindered so the bolt 9 is no longer positively retained in the recess 12 and the door may open. In its first protruding position (as shown in FIGS. 3 and 4) the latch member 13 covers the recess 12 and when the door is closed the bolt lies underneath the latch member 13 and at right angles thereto to lock the door.

A casing 23 is provided having an open end and a closed end and is provided with mounting holes 24. The latch member 13 is positioned within the casing 23 and protrudes through the open end when in its first protruded position.

The latch member per se, is formed with an angularly shaped strike bar 14 at its outer end and is provided with a rod 15 which extends through an aperture formed in the closed end of the casing 23. The strike bar 14 is illustrated protruding over the recess 12 with the sloping side facing outwards or away from the doorjamb to permit automatic closing and locking of the door in a closed position. A coil spring 16 is positioned over the rod 15 within the casing 23 to urge the latch member over the opening or recess 12 at all times. The rod 15 is threaded and is provided with an adjusting nut to cooperate with the threads on the rod 15 to regulate the amount of protrusion of the rod 15 from the closed end of the casing 23 and to regulate the tension on the latch member 13. At the outermost extremity of the rod 15, there is provided a knob 18 which may be manually actuated to disengage said latch member from the bolt 9 when it is desired to open the door from the inside.

So that the door may be opened by small children, etc., in case of emergency, a chain 19 is attached to the knob. It will be appreciated that, instead of a chain, any suitable member may be used.

In operation, when a key is inserted in the lock and turned counterclockwise (as seen in FIG. 1), it rotates the pinion 8 which operates the rack 10 and withdraws the bolt 9 from the recess. The door is then pushed open. To remove the key from the lock it is essential to return the key to its original extended position, thus returning the bolt 9 also to its original extended position. When the door is closed the bolt 9 strikes against the bevel end of the strike bar 14 of the latch member 13, causing the latch 13 to be urged into the casing 23. When the bolt 9 enters the recess 12, the latch member 13 is freed and, because of the spring, returns to its original position overlying the bolt 9 and retaining the door in the locked position.

To open the door from inside it is simply necessary to pull down the knob 18 (FIG. 4) to contract the spring 16 and clear the strike bar 14 of the latch member 13 of the bolt 9; the door is then pulled open by means of a handle (not shown in the drawings).

It will be appreciated that there has been described a door lock in which it is impossible to leave the door lock unlocked since to remove the key from the barrel, it must be returned to its original position and this returns the lock bar to its locked position. The spring-actuated strike bar 14 cooperates with the lock bar 9 to lock the door and the strike bar 14 is easily operated from the inside since the spring 16 need only be sufficiently strong to return the strike bar 14 to its original position when the combined door lock and night latch is operated.

The door lock, when constructed, should be strong and durable, easy to operate and completely foolproof since it is impossible to remove the key from the barrel without returning the bolt or lock bar to its original position after unlocking the door.

it is believed that the construction and advantages have been fully set forth and that further detailed description is not required.

While the preferred embodiment of the invention has been disclosed, it is to be understood that minor modifications may be restored to without departing from the spirit of the inven- UOH.

lclaim:

l. A combined door lock and night latch comprising:

i. a door lock comprising a. a plate adapted to be mounted on the inside face of a door;

b. a pin tumbler cylinder lock extending through said plate and operated by a key which is insertable and removable therefrom only when the cylinder is at one designated position;

c. a shaft member extending from said pin tumbler cylinder lock to project beyond said inside face of the door;

d. a pinion fixed to said shaft member;

e. a bolt provided with a rack adapted to engage said pinion for operation of said bolt;

f. guides to retain said bolt in a substantially horizontally slidably movable position;

ii. a recess adapted to be provided in the jamb of a doorframe and into which said bolt is adapted to slide; and

iii. latch means mounted on the said doorjamb to retain said bolt in said recess in said jamb when said door is closed said latch means comprising:

g. a retractable latch member, movable perpendicularly to said bolt between a first protruding position in which said bolt is positively retained in said recess and a second retracted position in which said bolt is no longer positively retained in said recess and permitting opening of the door;

h. a rodlike member connected to said latch member and extending away from said recess; and

i. a chainlike member connected to said rodlike member and hanging down therefrom, whereby on pulling of said chainlike member, said latch member is moved to its second, retracted position to enable emergency opening of said door.

2. A door lock according to claim 1 wherein said latch member has an angularly shaped strike bar protruding over said recess with the sloping side thereof facing outwards to permit automatic closing and locking of the door in a closed position.

3. A door lock according to claim 1 wherein:

a. said latch means includes a casing having a lower closed end and an upper open end;

b. said latch member being position within said casing and capable of protruding through said open end when in its first protruding position;

c. an aperture formed in said closed end, said rodlike member protruding through said aperture; and

d. a coil spring disposed over said rodlike member within said casing to urge said latch member into said first protruding position.

4. A door lock according to claim 3 including a nut to cooperate with threads on said rod to regulate the amount of protrusion of said rod from said aperture in said closed end of said casing and to adjust the tension on said spring and a knob positioned at the outer extremity of said rod to facilitate manual operation of said latch means. 

1. A combined door lock and night latch comprising: i. a door lock comprising a. a plate adapted to be mounted on the inside face of a door; b. a pin tumbler cylinder lock extending through said plate and operated by a key which is insertable and removable therefrom only when the cylinder is at one designated position; c. a shaft member extending from said pin tumbler cylinder lock to project beyond said inside face of the door; d. a pinion fixed to said shaft member; e. a bolt provided with a rack adapted to engage said pinion for operation of said bolt; f. guides to retain said bolt in a substantially horizontally slidably movable position; ii. a recess adapted to be provided in the jamb of a doorframe and into which said bolt is adapted to slide; and iii. latch means mounted on the said doorjamb to retain said bolt in said recess in said jamb when said door is closed said latch means comprising: g. a retractable latch member, movable perpendicularly to said bolt between a first protruding position in which said bolt is positively retained in said recess and a second retracted position in which said bolt is no longer positively retained in said recess and permitting opening of the door; h. a rodlike member connected to said latch member and extending away from said recess; and i. a chainlike member connected to said rodlike member and hanging down therefrom, whereby on pulling of said chainlike member, said latch member is moved to its second, retracted position to enable emergency opening of said door.
 2. A door lock according to claim 1 wherein said latch member has an angularly shaped strike bar protruding over said recess with the sloping side thereof facing outwards to permit automatic closing and locking of the door in a closed position.
 3. A door lock according to claim 1 wherein: a. said latch means includes a casing having a lower closed end and an upper open end; b. said latch member being position within said casing and capable of protruding through said open end when in its first protruding position; c. an aperture formed in said closed end, said rodlike member protruding through said aperture; and d. a coil spring disposed over saiD rodlike member within said casing to urge said latch member into said first protruding position.
 4. A door lock according to claim 3 including a nut to cooperate with threads on said rod to regulate the amount of protrusion of said rod from said aperture in said closed end of said casing and to adjust the tension on said spring and a knob positioned at the outer extremity of said rod to facilitate manual operation of said latch means. 